In the operation of a system that utilizes multiple data streams, such as multiple media data streams for display. The data may include data protected by High-bandwidth Digital Content Protection (HDCP) data, which is referred to herein as HDCP data. Communicating multiple media data streams may include a flow of content between a transmitting authority (e.g., cable television or satellite companies) and a receiving device (e.g., a television (TV)) via a transmission device (e.g., cable/satellite signal transmission device) through a High-Definition Multimedia Interface (HDMI).
Picture-in-picture (PiP) is a feature of some video transmitters and receivers in which one programming channel is displayed on a full screen of a receiving device (e.g., television) at the same time as one or more other channels are displayed in inset windows of the full display screen. This technique allows receiving device viewers to see multiple channels in a single screen by mixing multiple video streams. However, since PiP requires a great deal of memory, it is primarily used for and implemented on general-purpose processor-based platforms that employ relatively large amounts of memory and are not suitable for smaller platforms, such as an Application-Specific Integrated Circuit (ASIC)-based platform. ASIC refers to integrated circuit that is not used for general purpose; rather, it is customized for a particular use (e.g., customized and particular for use with handheld devices, smart phones, etc.). Given that an ASIC-based platform is customized for a particular use, it does not contain memory large enough to accommodate a conventional implementation of PIP.
FIG. 1 illustrates a conventional mechanism for generating picture-in-picture video from multiple video streams. As illustrated, two incoming videos or video streams 102, 104 enter PiP processing area 106 as one video stream 102 is selected as main video 108 by the viewer, while the other video stream 2 104 is selected to be shown as sub video 110. Video stream 102 passes through main channel selection 112 and emerges main video 108 without any changes to it, such as with regard to its size, etc. Video stream 104, however, passes through sub channel selection 114 and then on to down sampling 116 where it is down-sampled and emerges as sub video 110. Down-sampling 116 refers to reduction in or sampling down of the image size of video stream 104 by a certain amount or ratio resulting in generation of sub video 110 which, as illustrated, is much smaller than the original video stream 104. Both videos 108, 110 are then put through the conventional video mixing process 118 which merges the two images 108, 110 to be displayed as main video 108 and sub video 110 on a single display screen, as illustrated.
FIG. 2 illustrates a conventional picture-in-picture implementation 200 designed to operate on a processor-based platform. Video or video streams 202, 204 enter chip 214 through video interfaces 206, 208 (e.g., HDMI), respectively, on to processor 210. Processor 210 receives and reads the original videos 202, 204 from their channels and stores them in memory 216. Processor 210 then perform down-sampling algorithm and stores the results, including main video 218 and down-sampled sub video 220, back in memory 216. Main video 218 and sub video 220 are then merged together by processor 210 to generate a single final image 222 that contains both the main video 218 and sub video 220. As illustrated, this conventional implementation 200 requires a rather large memory 216 to store at least one video image, main video 218, and in many cases multiple video images 218, 220. This PiP implementation 200 only works with a large-capacity external memory device 216, resulting in high manufacturing cost for television systems having a PiP feature and making it unsuitable for smaller devices, such as cellular phones.